Tuesday, April 27, 2010

Virgin olive oil changes gene activity

Previous studies have shown a Mediterranean diet is associated with lower risks of all major diseases, but a small size study published in the open access journal BMC Genomics shed new light on how virgin olive oil influences certain genes that promote inflammation and can lead to heart disease.

Spanish researchers gave 20 volunteers with metabolic syndrome 2 breakfasts containing virgin olive oil with either high or low levels of phenols randomly on 2 separate days with a week apart. Both researchers and participants did not know who had received which breakfast. The researchers then measured the changes in the gene expression after the breakfasts and found that 39 genes are involved in the inflammation process (that has a role in the build-up of fatty deposits in the blood vessels ) and 35 of them were less active after eating the high-phenol virgin olive oil.

The researchers concluded that the study could partly explain why the risk in cardiovascular disease is reduced in Mediterranean countries where the diet is rich in virgin oliver oil.

Critics say that this study helps our understanding of the effect of olive oil on gene activity but it is difficult to confirm that the changes in gene activity is responsible for the reduction in risk of cardiovascular disease. The small size of the study, all participants with metabolic syndrome, gene expression after one meal and the lack of follow up for long-term outcomes are just some of the limitations that may affect the results of the study.

Source : Antonio Camargo, Juan Ruano, Juan M Fernandez, Laurence D Parnell, Anabel Jimenez, Monica Santos-Gonzalez, Carmen Marin, Pablo Perez-Martinez, Marino Uceda, Jose Lopez-Miranda and Francisco Perez-Jimenez. "Gene expression changes in mononuclear cells from patients with metabolic syndrome after acute intake of phenol-rich virgin olive oil". BMC Genomics, 2010

Too much added sugars may increase heart disease risk

A new JAMA study found that consuming a higher amount of added sugars in processed foods may increase cardiovascular disease risk factors.

The study analysed the US government nutritional data and blood lipid levels in more than 6000 adults and found that the highest consumption of added sugars was 46 teaspoons per day and the lowest was about 3 teaspoons daily. It also found that high consumption of added sugars was significantly correlated to lower levels of good cholesterol (high-density lipoprotein cholesterol, HDL-C) and higher levels of triglycerides, which are important risk factors for cardiovascular disease.

The authors said that this is the first study that examined the the association between added sugars consumption and lipid measures and found that total consumption of sugars in the US has substantially increased. People should cut down their added sugars consumption and further studies on the effect of reducing added sugars and other carbohydrates on lipid profiles are needed.

Source: J. A. Welsh, A. Sharma, J. L. Abramson, V. Vaccarino, C. Gillespie, M. B. Vos. "Caloric Sweetener Consumption and Dyslipidemia Among US Adults". JAMA 2010; 303 (15): 1490 (Full text via Athens)

Monday, April 26, 2010

Should aspirin be used for migraine relief?

A new Cochrane systematic review found that high dose aspirin can reduce migraine headache within 2 hours.


The review compared the use of aspirin to placebo or other migraine drugs including 13 studies and 4222 patients with migraine attacks. The amount of aspirin used in these studies varied between 900 - 1000 mg. Patients were randomly assigned to either a single dose of aspirin or a placebo or an active drug.

Researchers found that 24% of aspirin users were pain-free within 2 hours comapred to 11% of placebo users, aspirin also reduced the symptoms of nausea and vomiting, but aspirin plus antiemetic reduced these symptoms significantly compared with placebo. They concluded that 1000 mg of aspirin is effective for migraine relief, similar to the effect with sumatriptan.


Critics say that it is important to note that the over-the-counter standard aspirin is only 75mg and evidence has shown that regular use of aspirin may increase stomach problem or bleeding, taking high dose aspirin may increase these side effects. Also the effectiveness of aspirin may not apply to everyone as only a quarter of patients in these studies were pain-free after 2 hours.


Source : Kirthi V, Derry S, Moore RA, McQuay HJ. "Aspirin with or without an antiemetic for acute migraine headaches in adults (Review)". The Cochrane Library 2010, Issue 4

Tuesday, April 20, 2010

Do multivitamin tablets increase breast cancer risk?

Multivitamin supplements are widely used, but a large study involving 35,000 Swedish women aged 49 to 83 found that those who regularly took multivitamins had a higher risk of breast cancer than women who did not.


Based on self-reported questionnaire data, the researchers analysed the women's use of multivitamins as well as details about their health and lifestyle, followed up for 9.5 years until December 2007 to assess the cancer risk. They found that women who took multivitamins were 19% more likely to develop breast cancer than non-users. They also found that women who had taken these supplements for 3 years or more and those who took 7 or more pills a week were at increased risk of breast cancer than non-users, however the increase was very small.


The researchers concluded that "multivitamin use is associated with an increased risk of breast cancer" but they noted that other studies have had conflicting results. The authors said that this study carries an important public health message and recommend women to eat healthy diet instead of using supplements.

Critics say that this study was based on self-reported data that could affect the results. Further research is needed, it is not possible to say which of the supplements may contribute to breast cancer risk.

Source: "Multivitamin use and breast cancer incidence in a prospective cohort of Swedish women". American Journal of Clinical Nutrition, March 24 2010 (full text via Athens)

Brisk walking can reduce stroke risk in women

A large study published in Stroke found that women who walked two or more hours a week or walked briskly lowered the risk of stroke by more than a third.


The researchers followed nearly 40000 women aged over 44 for about 12 years to investigate the link between the levels of physical actitivity and the risk of having a stroke. The participants reported periodically on their physical activities via a questionnaire. 579 women had a stroke during the follow-up years.


The researchers said they have found a borderline significant link between the time spent on physical activities and stroke risk but they did not find a link between vigorous activity and reduced stroke risk. The lead author said the study was observational and physical activity was self-reported, further study is needed on more hemorrhagic strokes and with more ethnically diverse women.

Source: "Physical Activity and Risk of Stroke in Women". Stroke, published online April 2010 DOI

Monday, April 19, 2010

High GI food may increase women's heart risk

According to a study published in the Archives of Internal Medicine, consuming carbohydrates with high glycemic index (GI) such as white bread, sweets and sugary cereals appears to be associated with the risk of coronary heart disease in women but not men. However, not all carbohydrates have the same effect on blood glucose levels.

Italian researchers studied 47,749 adult men and women who completed dietary questinnaires. They found that women who consumed the most carbohydrates overall had approximately twice the risk of heart disease as those consumed the least. Women whose diet had the highest glycemic load had 2.24 times the risk of heart disease than those with the lowest glycemic load.

The researchers concluded "we tentatively suggest that the adverse effects of a high GI diet in women are medicated by sex-related differences in lipoprotein and glocuse metabolism" and that further studies are needed to verify the link between high-glucose foods and cardiovascular disease in men.

Source: "Dietary Glycemic Load and Index and Risk of Coronary Heart Disease in a Large Italian Cohort: The EPICOR Study". Arch Intern Med, 2010; 170 (7): 640-647

Maternal deaths drop worldwide

The Lancet published an article online on 12 April that has found significant decline in maternal deaths worldwide. This finding however is very different from a new UN study claiming that the number of women dying in childbirth remains high at 500,000 a year.

The Lancet study is based on the data collected from 181 countries between 1980 and 2008 provided by the Univeristy of Washington and found that maternal deaths have fallen from about 500,000(1980) to about 343,000 (2008). Many experts are surprised by the finding as they have assumed little progress made in this area.

According to the journal editor, The Lancet was pressured by some advocate groups to delay the publication of the new finding fearing loss of funding, but he said that the new data shows improvements and should encourage politicians to spend more on women's health.

Source: "Maternal mortality for 181 countries, 1980—2008: a systematic analysis of progress towards Millennium Development Goal 5". The Lancet, Early Online Publication, 12 April 2010

Should patients be given a voice in drug-safety reporting?

An oncologist, Ethan Basch, wrote in the March 11 issue of NEJM, that current clinician-based approach to adverse symptom reporting is based on clinicians’ impressions of patients’ symptoms, not on patients’ direct symptom reports. He said that evidence has shown that clinicians responsible for collecting and reporting adverse symptoms in clinical trials systematically downgrade the severity of patients’ symptoms and often miss the side effects, as a result vital information about drug safety is missing .

He argued that doctors, researchers and regulators should pay more attention to patients’ symptom reports while taking a drug because it could help identify symptoms earlier during a course of treatment and reduce preventable harm.

He said that technologies are now available for collecting information directly from patients and patients should be given the tools to self-report adverse symptoms in clinical trials such as online reporting between clinic visits, this can capture a lot of baseline symptoms before the drug is approved including those symptoms that researchers did not anticipate.

He concluded that “patient self-reporting would enhance the capture of subjective elements of safety information and patients are entitled to know the impressions of their peers”, such information would also help clinicians to evaluate the drugs.

Source: "The Missing Voice of Patients in Drug-Safety Reporting". NEJM 362(10):865-869 (full text via Athens)